Figure 1From: P6 acupoint stimulation for prevention of postoperative nausea and vomiting in patients undergoing craniotomy: study protocol for a randomized controlled trial Trial flow chart. If a patient can not complete the study due to death, re-operation, unconsciousness or cognitive impairment, the patient will be considered a lost case and recorded as an occurrence of PONV. PONV, postoperative nausea and vomiting; TENS, transcutaneous electrical nerve stimulation.Back to article page